cantoris /kænˈtɔːɹɪs/noun 2adjective 1 noun2 •That half of the choir singing cantoris parts, collectively. •The lower of two choral voice parts sung when a part splits into two; traditionally sung by members of the choir on the cantoris side.All the extant voices participate fully in the decani-cantoris split at that point, so one is tempted to assume that the tenors split into decani and cantoris parts as well. — 1988 adjective1 •Of the side of the chancel, apse, altar or choir on which the cantor's (later precentor's) stall is placed (the left hand side to a person facing the altar);one accompanyist, let us suppose him seated on the Cantoris side, facing the Decani Organ[…] — 1858